La Trobe biochemist Dr Megan Maher, in collaboration with researchers at the La Trobe Institute for Molecular Science (LIMS), the Centenary Institute, the University of Sydney and the University of Queensland, has described the crystal structure of a protein complex active in electron transfer.
Critical to life
Electrons are particles that form part of the structure of every atom. In biological systems, electrons must 'flow' (much like an electrical current) from one protein to another. This action is critical to the most fundamental processes of life, including respiration in mammals and photosynthesis in plants.
"The process of electron transfer between proteins is a little like a relay," explained Dr Maher. "The electron is the baton and the proteins are the runners. Like runners in a relay, the proteins must come together and quickly exchange the baton so it can be passed to the next runner in the race."
Dr Maher and her team were able to capture the proteins together in the process of exchanging the electron by using X-ray crystallography; a technique that allows scientists to see the inner workings of atoms and molecules.
"In the case of protein crystallography, we grow crystals of proteins and shine 'light' through them (in this case, high-intensity X-rays) in order to discover the positions of atoms and therefore protein molecules in the crystal," said Dr Maher. "We can then map the three-dimensional architecture of a protein. Once we know what a protein looks like, we can understand how it works."
The snapshot of electron transfer, the first of its kind, was published in the prestigious international journal eLife. It reveals that while the exchange process is rapid, the proteins interact much more extensively than scientists had previously thought. "Changes to the shape of one of the proteins during the exchange allow the electrons to be transferred quickly," said Dr Maher.